8, 13, 14, 16, 16, 18, 18, 20, 20,22, 30*30 is the only outlier Examples Outliers Data that are more than 1.5 times the value of the interquartile range beyond the quartiles Interquartile Range difference between the upper and lower quartiles

IQR = Q3 – Q1

Small IQR – data is close together

Large IQR – data is more spread out Quartiles separate the original set of data into four equal parts

Each of these parts contains one-fourth of the data Median separates the data into two equal parts.

Data can be further separated into quartiles... A.10 Compare and contrast multiple univariate data sets, using box-and-whisker plots Example Box and Whisker Plot Data organized and displayed by dividing a set of data into four parts using the median and quartiles Draw a box-and-whisker plot for the data: 14, 30, 16, 20, 18, 16, 20, 18, 22, 13, 8 Step 1: Order from least to greatest. Determine quartiles.

8, 13, 14, 16, 16, 18, 18, 20, 20,22, 30

Q1 Q2(Median) Q3IQR = Q3 – Q1 = 20 – 14 = 6 The prices at Shop A are more expensiveand the prices there are more varied Both sales reps have a median sales of 14 cars. Theamount of cars that B sells varies much more than A . The lower 25% of B's sales is much less than the lower 25%of A's sales.